There are some factors that cause the ICO fail. First is bad project ideas. The tokens aren't actually deemed to be useful by enough people, it is hard to successfully promote the usage of the coins/tokens. Second is technology issues, understanding all the technical aspects of the blockchain technology behind the projects is advisable but it is not always practical. These two causes potentially make some ICOs failing before starting. Therefore, investors need to look out for when investing ICO whether or not the tokens is useful in the real world.